I checked out a painting from the library to hang in my home office, but when I got it home it was much too big for my wall. When I took it back the library hung it on a wall in the main reading room and there it looked too small. The explanation of why the same picture can look both too small and too big is the same as the explanation for which story from your text.

• Walmart case

Should you drive to Walmart to save $10 on a $20 clock radio?

You are about to buy a clock radio at the nearby campus store for $20 when a friend tells you that the very same radio is on sale at Walmart for only $10. If Walmart is a 15 minute drive away, where would you buy the radio? (If it fails under warranty, you must send it to the manufacturer for repairs, no matter where you bought it.)

Should you drive downtown to save $10 on a$1000 television set?

You are about to buy a new television set at the nearby campus store for $1010 when a friend tells you that the very same set is on sale at Walmart for only $1000. If Walmart is a 15 minute drive away, where would you buy the television? (Again, repairs under warranty would entail sending the set to the manufacturer in each case.)

• Should I go skiing today?

There is a ski area near your campus. From experience you know that a day on the slopes is worth $60 to you.The charge for the day is $40 (which includes bus fare, lift ticket, and equipment). However, this is not theonly cost of going skiing.

Suppose the best alternative is your new job as a professor's research assistant. The job pays $45 per day, and you like it just well enough to be willing to do it for free.

"Should I go skiing or work as a research assistant?"

Suppose instead that your job is to scrapeplates in the dining hall for the same pay,$45/day, and that the job is so unpleasant that you would be unwilling to do it for less than $30/day. Assuming your manager at the dining hall permits you to take a day off whenever you want

• Should I drive to Boston or take a bus?

You are planning a 250 mile trip to Boston.Except for the cost, you are completelyindifferent between driving and taking thebus. Bus fare is $100. You don't know howmuch it would cost to drive your car, so youcall Hertz for an estimate. Hertz tells you that for your make of car the costs of a typical 10,000 mile driving year are as follows:

insurance $1,000

Interest $2,000

Fuel & Oil $1,000

Maintenance $1,000

Total $5,000

Suppose you calculate that these costs come to $0.50/mile and use this figure tocompute that the 250 mile trip will cost you $125 by car. And since this is morethan the $100 bus fare, you decide to take the bus.

• How many boats should Tom launch?

Tom manages a small fishing fleet of threeboats. His current daily cost of operations,including boat rentals and fishermen's wages, is $300, or an average of $100 per boat launched. His daily total revenue, or benefit, from the sale of fish is currently $600, or an average of $200 per boat launched. Tom decides that since his cost per boat is less than his revenue per boat, he should launch another boat. Is this a sound decision?

• More than one of the above.

which case is the same as question on the top?